Resuggestion, thanks to K1ng for the info!

Sale 1:

https://backpack.tf/profiles/76561198101623903#!/compare/1569628800/1569715200

https://backpack.tf/profiles/76561198002757046#!/compare/1569628800/1569715200

QS

sale 2:

https://backpack.tf/profiles/76561198002757046#!/compare/1570060800/1570147200

https://backpack.tf/profiles/76561198175767811#!/compare/1512864000/1570147200

Sold for 9 keys

sale 3:

https://backpack.tf/profiles/76561198175767811#!/compare/1570752000/1571443200

https://backpack.tf/profiles/76561198125791160#!/compare/1570838400/1570924800

Sold with 5 keys for DBD Whoopee

Whoopee mini:

https://backpack.tf/suggestion/5db9494c67807209c972f096

Suggestion for 13.5 keys

total is 8.5 keys

sale 4:

https://backpack.tf/profiles/76561198298066555#!/compare/1564099200/1566000000

https://backpack.tf/profiles/76561198374845371#!/compare/1566000000/1566864000

untrace

sale 5:

https://backpack.tf/item/2326401313

all gambling

Sale 6:

https://backpack.tf/profiles/76561198078780040#!/compare/1566000000/1566086400

https://backpack.tf/profiles/76561198302161698#!/compare/1566000000/1566086400

Sold for 7 keys

Sale 7:

https://backpack.tf/profiles/76561198302161698#!/compare/1566259200/1566345600

https://backpack.tf/profiles/76561198320346037#!/compare/1566259200/1566345600

Sold for hoS Handcraft(13)

Sale 8:

https://backpack.tf/profiles/76561198320346037#!/compare/1566432000/1566518400

https://backpack.tf/profiles/76561198415180580#!/compare/1566432000/1566518400

sold for CPS Marauder

use there

https://bot.tf/stats/listings/425NKRGQ

B/O of 12 keys

sale 9:

https://backpack.tf/profiles/76561198071711499#!/compare/1569110400/1569196800

https://backpack.tf/profiles/76561198337734785#!/compare/1569024000/1569110400

QS

Sale 10:

https://backpack.tf/profiles/76561198318287187#!/compare/1566000000/1566086400

https://backpack.tf/profiles/76561198337734785#!/compare/1565913600/1566000000

QS

sale 11:

https://backpack.tf/profiles/76561198269500928#!/compare/1571011200/1571097600

https://backpack.tf/profiles/76561198269337198#!/compare/1570752000/1571011200

Untrace

sale 12:

https://backpack.tf/profiles/76561198269337198#!/compare/1571788800/1571875200

https://backpack.tf/profiles/76561198101915413#!/compare/1571788800/1571875200

Bulkj

sale 13:

https://backpack.tf/profiles/76561198101915413#!/compare/1571961600/1572048000

https://backpack.tf/profiles/76561198101084804#!/compare/1571961600/1572048000

Bulk

sale 14:

https://backpack.tf/profiles/76561198101084804#!/compare/1572048000/1572134400

https://backpack.tf/profiles/76561198298344239#!/compare/1572048000/1572134400

Sold for Aussie Axe(~7)

Sale 15:

https://backpack.tf/profiles/76561198298344239#!/compare/1572048000/1572134400

https://backpack.tf/profiles/76561198355667850#!/compare/1572048000/1572134400

Sold with ~2 keys in sweets for Aces Company Man

use there

Sale 16:

https://backpack.tf/profiles/76561198355667850#!/compare/1572134400/1572220800

https://backpack.tf/profiles/76561198167418363#!/compare/1571788800/1572134400

Sold for 8 keys

sale 17:

https://backpack.tf/profiles/76561198167418363#!/compare/1571788800/1572134400

https://backpack.tf/profiles/76561198120672630#!/compare/1572048000/1572134400

Sold with ~4.5 keys in sweets for C9 Tit Tyro

Tyro Mini:

https://backpack.tf/suggestion/5db942a2678072048777b169

Suggestion for 12 keys

Total is 7.5 keys

Sale 18:

https://backpack.tf/profiles/76561198855892118#!/compare/1567296000/1567382400

https://backpack.tf/profiles/76561198153650248#!/compare/1566864000/1567382400

untrace

Sale 19:

https://marketplace.tf/items/tf2/30019;5;u58

$21 / $1.83 = 11.48 keys

$18.95 / $1.81 = 10.47 keys

$18.95 / $1.82 = 10.41 keys

total sales @:

7, 7, 7.5, 8, 8.5, 9, 10.41, 10.47, 11.48, 13 keys

buyers up to ~6 keys,

sellers down to 11 keys,

calling 7 low,

11.48 high,

K1ng's Part:

There were ~6 keys in sweets added in sale 17, not 4.5. This should be 8-10.5.

Taking 8- 10.5 keys